Spectators in a Chicago courtroom erupted with anger and disgust after a Cook County judge acquitted a veteran Chicago police detective who fatally shot an unarmed woman three years ago.

Police officer Dante Servin has been on desk duty since he fatally shot 22-year-old Rekia Boyd during an encounter in March 2012. Boyd was with three other people in a Chicago park when Servin approached in his patrol vehicle while off duty and asked the group to “keep the noise down,” WLS-TV reported.

One of the individuals in the group — later identified as Antonio Cross — pulled something from his waistband, prompting Servin to open fire on the crowd. Cross was struck in his hand; Boyd was hit in the back of her head.

The only item recovered from the scene was a cellphone, prosecutors said. A weapon was never found.

Servin was later charged with involuntary manslaughter, reckless discharge of a firearm and reckless conduct, DNAInfo.com reported. His defense attorneys never disputed that Servin fired the shots that fatally wounded Boyd, but said he did so because he feared for his life and that his conduct was not reckless. Prosecutors argued the officer thought the cellphone was a weapon and he “heard a bang and felt something hit the back of his head,” DNAInfo.com said.

Servin’s bench trial — one where a judge, not a jury, determines innocence or guilt — began in early April. Cook County Judge Dennis Porter delivered his directed verdict on Monday before Servin’s defense had an opportunity to present a case.

“This is a court of law, not a court of emotion,” Porter said. The judge said prosecutors had not proven that Servin acted recklessly when he fired the shot that killed Boyd.

Several of Boyd’s family members were present in court when the verdict was read. Some immediately expressed outrage at the officer’s acquittal.

Sutton continued shouting as he was led out of courtroom while relatives of the veteran detective hugged the acquitted officer. He continued expressing contempt for the judge’s ruling long after he was removed from the courtroom.

“When we walked in, we already knew we lost,” Sutton told reporters. “I thought that maybe the judge would grow a heart, but just like the Tin Man, he never had one.”

Legal experts say the judge’s decision to render a verdict before the defense had a chance to present a case is an unusual, but not rare, move. Law professor Richard Kling told DNAInfo.com the judge likely felt prosecutors charged the officer with the wrong crime.

“They charged him with reckless conduct, and what Judge Porter said was this wasn’t reckless, it was intentional,” Kling said. “It ended up hurting them.”

Kling said the judge likely took the preponderance of evidence under advisement before rendering his verdict of not guilty because “even if you take all the evidence in favor of the state, they (the prosecutors) haven’t proven what they need to.”

The City of Chicago paid the Boyd family more than $4 million in order to settle a wrongful death lawsuit filed in 2013.